Ok I compared the 2 execution plans....

one execution plan from when the max server memory was 26 gig and one from when the max server memory was set to 54 gig....there is definitley a difference in one of the query execution plans....

I have attached it....

Question: why would sql give it different execution plans just b/c I changed the max server memory.

Also to add, I checked the event logs on the server...all clean..app, system and security...

SHould I set locked pages in memory to the service account that is running sql since this is 64 bit?